1. Field of the Invention
The present invention relates to a method for processing duplicated data, and more particularly to a method for determining whether duplicated data exists.
2. Related Art
Data de-duplication is a data reduction technology and generally used for a disk-based backup system for the main purpose of reducing storage capacity used in a storage system. A working mode of the data de-duplication is searching for duplicated tanks of viable sizes at different locations in different files within a certain period of time. The duplicated tanks may be replaced with an indicator. A large quantity of redundant data always exists in the storage system. A de-duplication technology can be adopted to reduce stored data to 1/20 of the original stored data, so as to obtain more backup space.
Data to be stored is stored in a server, so a client needs to transport data confirmed as unduplicated to the server. When the server confirms the data as the unduplicated new data, the server first registers a fingerprint value of new data and then receives and stores the new data. Different clients may correspond to the same data, so more backup space can be conserved. However, in a multi-client system, when one client is adding and transmitting new backup data, other clients may intend to query whether the same backup data is duplicated. In this way, other clients may consider that the duplicated data exists but cannot find the corresponding duplicated data. Especially, when addition fails since new data being added is faulty, but other clients discard own data, the addition completely and irremediably fails.